how do i fix this error?

[RUDEBWOY]

The file nv4_disp.dll is not digitally signed, which means that it has not been tested by Microsoft's Windows Hardware Quality Labs (WHQL). You may be able to get a WHQL logo'd driver from the hardware manufacturer.
To test DirectDraw functionality, click the "Test DirectDraw" button above.
To test Direct3D functionality, click the "Test Direct3D" button above.

im running a pci express 7600 gs...

i get this when i check dxidiag command.

 

[NFSFAN]

Go to this link http://www.nvidia.com/object/winxp_2k_91.47.html
After is done downloading, uninstall your old NVIDIA driver from Add Remove Programs. When asked for restart don't restart, press No. Then go to this link
http://www.drivercleaner.net/download.php?site=1&file=DCProSetup_15.zip
Download and extract the program. Install it, and run it. Under the "Cleaning Selection" click on the drop down box and select nVidia. Press Start, after it is done it should say Cleaning Finished. Restart you PC. Install the driver you downloaded from the first link, and restart your PC. The error should be gone. Cheers